Galvanneal Sheet Metal

Description galvannealed steel has very similar properties as standard galvanized but the surface has a more porous and abrasive finish that more readily accepts paint.

Galvanneal sheet metal.

Sacrificial coatings are an excellent way to protect an underlying base material from the effects of corrosion. One notable process called galvannealing. Galvannealed steel zinc iron alloy coated by the hot dip process followed by heating the steel to induce diffusion alloying between the molten zinc coating and the steel. Galvanneal is the main paintgrip used in the duct fabrication industry taking the place of phos bond which used to be the only option many years ago.

Galvannealed steel is a matte uniform grey color which can be easily painted. Galvannealed sheet is carbon steel coated with zinc on both sides applied to the metal through a continuous hot dip process. Avoid painted metal degradation with resilient galvannealed steel sheet and coil products from alliance steel. It is vastly used for many miscellaneous applications.

As the steel emerges from the molten zinc bath all excess zinc is removed from the surface using heated air knives. In comparison to galvanized steel the coating is harder and more brittle. This is preferred over galvanized if the metal is to be painted. The resulting finish is a dull matte surface.

As the metal strip exits the coating bath the zinc is subjected to an in line heat treatment that converts the entire coating to a zinc iron alloy giving the sheet improved surface finish so it can be painted. Immediately after the hot dip process the metal is exposed to a heat treatment that allows the iron from the base metal to further diffuse into the zinc creating a zinc iron alloy layer. A40 galvanneal is the most commonly used coating while a60 is less popular because it tends to be too powdery when it sits unpainted too long. Galvannealed or galvanneal galvannealed steel is the result from the processes of galvanizing followed by annealing of sheet steel.

Galvannealed steel is very conducive to forming welding and allows for excellent paint adhesion. Has no protective film. There are however several different processes to apply this zinc layer. The process produces a uniform zinc coating on both sides of the product.

The steel is then annealed which converts the zinc into a zinc alloy coating that offers increased corrosion and scratch resistance. In comparison to galvanized steel the coating is harder and more brittle. Galvannealed steel is created by a hot dip coating process. From there the steel continues through an annealing furnace converting the zinc into a zinc iron alloy coating galvanneal.

A particularly popular combination is coating carbon steel with a layer of zinc known as galvanized steel. Galvanneal steel is produced on a continuous hot dipped galvanized steel line.